Gas burner construction



April 8, 1969 c. GORMAN 3,437,414

GAS BURNER CONSTRUCTION Filed March 13, 1967 United States Patent 3,437,414 GAS BURNER CONSTRUCTION Christopher B. Gorman, Oakland, Calif., assignor to Ransome Torch & Burner 'Co., a corporation Filed Mar. 13, 1967, Ser. No. 622,777 Int. Cl. F23n /08 U Cl. 43179 2 Claims ABSTRACT OF THE DISCLOSURE A gas burner having a self-ignition device and a sensing device to operate a safety gas shut-off mechanism is provided with shields to prevent the sensor from responding to the self-ignition device and to prevent wind from extinguishing the flame on the burner.

My invention relates to gas burners and in particular to a self-igniting gas burner utilizing a sensing device to operate a safety gas shut-off mechanism.

When a gas burner utilizes a self-ignition device and relies on a sensor to operate a safety gas shut-off mechanism when there is no flame at the burner head, there is a possible danger that the sensor will respond to the self-ignition device alone, thus allowing the gas to flow when no flame is burning. The escaping the gas to flow cause asphyxiation or an explosion. The presence of a wind increases this danger both because it can blow out a burning flame and because it can upset the normal mixing process between gas and air which takes place in the venturi of the burner and cause a flame to go out. My invention deals with these problems.

It is thus an object of my invention to provide a gas burner utilizing a self-ignition device with a sensing device which will respond to a lighted burner but not to the self-ignition device.

Another object of my invention is to provide a gas burner utilizing a spark self-ignition device with an optical sensing device which will respond only to a lighted burner and not to a spark in the self-ignition device.

Another object of my invention is to provide a gas burner which is less likely to go out in the presence of a wind.

Another object of my invention is to provide a safe gas burner.

Still another object of my invention is to provide a generally improved gas burner.

Other objects together with the foregoing are attained in the embodiment of my invention which is described in the accompanying description and which is illustrated in the accompanying drawing, which is a side elevation of a gas burner construction utilizing my invention with portions in section and other portions shown schematically.

In the embodiment shown in the accompanying drawing a pilot burner 1 of generally conventional structure is supplied with gas from a source (not shown) as indicated by the arrow 2. The gas first passes through a remotely operated valve 3 of conventional design. The gas then passes through a pipe 4 into the venturi tube 5 of the burner 1.

The pipe 4 carries external threads 6 over its entire length except for a non-circular portion 7 which is engageable by a wrench. The end of the pipe 4 within the venturi tube 5 has an orifice tip 8 through which the gas is injected into the venturi tube 5. The venturi tube 5 has a mixing portion 9 followed abruptly by a narrow venturi region 10 which gradually expands toward the burner head 11. The mixing portion 9 is bounded by an annular member 12, one end 13 of which is open to the atmosphere except for an internally threaded piece 14 which is suspended on the axis 15 of the venturi tube by transverse struts (not shown). The end of the pipe 4 having the orifice tip 8 is screwed into these threads.

Also mounted on the threads 6 of the pipe 4 is a cupshaped shutter 16 which may be moved toward or away from the open end 13 of the mixing portion 9 along the threads '6 of the pipe 4 or may be locked in place by a lock nut 17. This cup-shaped shutter 16 has a circular planar base 1 8 having an internally threaded hole 19 through its center for mounting on the external threads 6 of the pipe 4 and a cylindrical sleeve 20 on the edge of the base 18 overlying the mixing portion 9 of the venturi tube 5 so as to shield the mixing portion 9 from the wind.

The end 21 of the venturi tube 5 remote from the mixing portion 9 is received in a mounting bracket 22 having a sleeve 23 and a tab 24 extending tangentially from the sleeve 23 through which screw holes 25 pass for mounting the burner 1 adjacent the object to be heated (not shown). Received in the other end of the mounting bracket 22 is a short tubular connector 2-6 to which is fastened the burner head 11. The burner head 11 is made up of a nozzle 27 which is cylindrical in shape with one end 28 closing about the tubular connection 26 and a grid 29 which is received in the other end of the nozzle 27 and supported by a step 30 protruding from the inside wall of the nozzle 27.

The grid 29 has a series of passages 31 about its circumference and another passage 32 along its axis 15 through which the gas-air mixture passes to be burned by a flame 33. The circumferential passages 31 are indentations in the circumferential wall 34 of the grid 29 parallel to its axis, and the axial passage 32 begins as a cylindrical hole 35 on the inside of the nozzle and expands to the circumferential wall 34 of the grid 29 through a series of conical sections 36.

Also mounted on the tubular connection 26 and held in place by the mounting bracket 22 and the burner head 11 is a plate 37. This plate 37 is circular in shape and has two holes passing through it, one, 38, through which the tubular connector 26 passes and the other, 39, through which a self-ignition device 40 passes. Fastened to the plate 37 is an internally threaded sleeve 41, the internal diameter of which is the same as that of the latter hole 39 and the end of which coincides with this hole. The axis 42 of this sleeve 41 is parallel to the axis 15 of the venturi tube 5.

The self-ignition device 40 is made up of an electrode 43 which passes through a suitable insulator 44 to a terminal 45. An externally threaded sleeve 46 having a noncircular portion 47 for engagement with a wrench surrounds a portion of the insulator 44 for mounting in the internally threaded sleeve 41 on the plate 37. The electrode 43 is shaped so that its end 48 remote from the terminal 45 is close enough to the burner head 11 for a spark to jump from the electrode 43 to the burner head 11 when a high voltage source (not shown) is attached to the terminal 45 by a suitable lead 49 and the burner head 11 is electrically grounded by suitable means (not shown).

The burner 1 is provided with a safety gas shut-off mechanism for shutting Off the gas when there is no flame at the burner head. An optical sensor 50 such as a sensitive electronic scanner is so positioned as to respond to the light emitted by a flame 33 at the burner head 11. A signal from the sensor 50 passes along a suitable conduit 51 to a control mechanism 52 of conventional design which opens or closes the remotely operated valve 3 by a signal through another suitable conduit 53. To prevent the optical sensor 50 from also reacting to the light emitted by sparks jumping the gap between the electrode 43 and the burner head 11 or the gap which would be created if the lead 49 were to fall a short distance from the terminal 45 (as shown), the burner head 11 and self-ignition device 40 are provided with one optical shield 54 and the terminal 45 is provided with another optical shield 55.

The shield 54 about the burner head 11 and self-ignition device 40 is a cylinder one end of which is fixed to the rim of the circular plate 37 and the other end of which is cut at an angle. The highest portion 56 of the cylinder end stands above most of a flame 33 at the burner head 11, thus shielding it from the wind and affording a dark background. The lowest portion 57, between the burner head 11 and the optical sensor 50, is low enough to allow the sensor 50 to receive light from a flame 33 at the burner head 11 but not low enough to allow the sensor 50 to receive light from a spark jumping between the electrode 43 and the burner head 11.

The shield 55 about the terminal 45 is a cylinder, one end of which is fastened to the insulator 44 and the other end of which extends sufiiciently far past the terminal 45 that the sensor 50 could receive no light from any spark which could jump to the terminal 45 from the high voltage lead 49 positioned near it; that is, the shield is longer than any possible spark. By the provision of these constructions, the sensor can respond only to a proper flame, and spark-induced false actuations of the sensor are avoided.

What is claimed is:

1. A gas burner construction comprising a burner head, means for supplying gas to said burner head for discharge therefrom, means for admitting air to said burner head, ignition means mounted on said burner head and including an electrode positioned adjacent the point of discharge of gas from said burner head and providing a spark gap between said electrode and said burner head, sensing means operably connected to said gas supplying means and responsive to the pressure of a flame at said burner head and to a spark at said spark gap, and means on said burner head for shielding said sensing means from said spark gap in which said sensing means is an optical sensor directed toward and in the line of sight of said spark gap and said spark-gap shielding means is a piece of opaque material positioned in said line of sight between said sensing means and said spark gap.

2. A gas burner construction as in claim 1 in which said spark-gap shielding means is a cylinder mounted on and surrounding said burner head and said ignition means and having one portion so shaped as to expose only the flame at said burner head to said sensing means.

References Cited UNITED STATES PATENTS 2,840,145 6/1958 Ator. 3,051,228 8/1962 Peoples et a1. 3,076,495 2/1963 Ray et al.

FREDERICK L. MATTESON, JR., Primary Examiner.

E. G. FAVORS, Assistant Examiner. 

